With the current depletion rate of petroleum resources, alternative sources of fuel are desired. Production of distillate fuel from biological resources is one desirable option since it minimizes greenhouse gas formation (e.g., carbon dioxide). See Pearce, “Fuels Gold,” New Scientist, 23 September, pp. 36-41, 2006.
Many distillate fuels prepared from biological resources are in the form of triglycerides (which have problems of high viscosity) or methyl esters of the fatty (carboxylic) acids derived from the triglyceride. These fuels are highly oxygenated and are quite different from conventional fuels. For example, they cannot be used as a jet fuel. See, e.g., Huber et al., “Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering,” Chem. Rev., vol. 106, pp. 4044-4098, 2006.
It is desirable to prepare fuels that are similar to conventional fuels (primarily hydrocarbons) from these biological resources. One approach, as described in United States Patent Application Serial No. 20040230085, is to convert the oxygenates into paraffins by a combination of hydrodexoygenation and isomerization this results in a paraffinic product that contains sufficient isoparaffin-s to achieve cold climate specifications.
Unfortunately, isoparaffinic distillate fuels are known to have poor lubricity properties. See, e.g., Vere, “Dilution Restores Lubricity,” SAE Journal, vol. 78(4), pp. 42-43, 1970. Conventional lubricity additives can be added to improve lubricity, but these are expensive, and from an environmental and/or process perspective, it is generally desirable to have as many components as possible derived from the biological resource.
As a result of the foregoing, an efficient, more cost-effective method of producing triglyceride-derived biofuels with sufficient lubricity is desirable.